rs397507435

chr13-32332449-G-Achr13-32332449-G-C

Variant summary

Our verdict is Likely benign. Variant got -1 ACMG points: 2P and 3B. PM2 BP4_Moderate BP6

The NM_000059.4(BRCA2):c.971G>A(p.Arg324Lys) variant causes a missense change involving the alteration of a non-conserved nucleotide. The variant allele was found at a frequency of 0.00000347 in 1,439,854 control chromosomes in the GnomAD database, with no homozygous occurrence. In-silico tool predicts a benign outcome for this variant. 13/19 in silico tools predict a benign outcome for this variant. Variant has been reported in ClinVar as Conflicting classifications of pathogenicity (no stars). Another variant affecting the same amino acid position, but resulting in a different missense (i.e. R324T) has been classified as Likely benign.

• Frequency:
  • Genomes: not found (cov: 32)
  • Exomes 𝑓: 0.0000035 (0 hom.)
• Consequence: BRCA2 NM_000059.4 missense
• Clinical Significance: Conflicting classifications of pathogenicity criteria provided, conflicting classifications U:7 B:2
• Conservation: PhyloP100: 1.58

Genes affected

BRCA2 (HGNC:1101): (BRCA2 DNA repair associated) Inherited mutations in BRCA1 and this gene, BRCA2, confer increased lifetime risk of developing breast or ovarian cancer. Both BRCA1 and BRCA2 are involved in maintenance of genome stability, specifically the homologous recombination pathway for double-strand DNA repair. The largest exon in both genes is exon 11, which harbors the most important and frequent mutations in breast cancer patients. The BRCA2 gene was found on chromosome 13q12.3 in human. The BRCA2 protein contains several copies of a 70 aa motif called the BRC motif, and these motifs mediate binding to the RAD51 recombinase which functions in DNA repair. BRCA2 is considered a tumor suppressor gene, as tumors with BRCA2 mutations generally exhibit loss of heterozygosity (LOH) of the wild-type allele. [provided by RefSeq, May 2020]

ACMG classification

Verdict is Likely_benign. Variant got -1 ACMG points.

• PM2: Very rare variant in population databases, with high coverage
• BP4: Computational evidence support a benign effect (MetaRNN=0.0694848).
• BP6: Variant 13-32332449-G-A is Benign according to our data. Variant chr13-32332449-G-A is described in ClinVar as [Conflicting_classifications_of_pathogenicity]. Clinvar id is 141234.We mark this variant Likely_benign, oryginal submissions are: {Uncertain_significance=7, Likely_benign=2}.

Transcripts

RefSeq

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	MANE	UniProt
BRCA2	NM_000059.4	c.971G>A	p.Arg324Lys	missense_variant	10/27	ENST00000380152.8

Ensembl

Gene	Transcript	HGVSc	HGVSp	Effect	#exon/exons	TSL	MANE	Appris	UniProt
BRCA2	ENST00000380152.8	c.971G>A	p.Arg324Lys	missense_variant	10/27	5	NM_000059.4	A2

Frequencies

GnomAD3 genomes Cov.: 32

GnomAD3 exomes AF: 0.0000172 AC: 4 AN: 232690 Hom.: 0 AF XY: 0.0000159 AC XY: 2 AN XY: 125782

Gnomad AFR exome AF: 0.00

Gnomad AMR exome AF: 0.000135

Gnomad ASJ exome AF: 0.00

Gnomad EAS exome AF: 0.00

Gnomad SAS exome AF: 0.00

Gnomad FIN exome AF: 0.00

Gnomad NFE exome AF: 0.00

Gnomad OTH exome AF: 0.00

GnomAD4 exome AF: 0.00000347 AC: 5 AN: 1439854 Hom.: 0 Cov.: 31 AF XY: 0.00000419 AC XY: 3 AN XY: 715590

Gnomad4 AFR exome AF: 0.00

Gnomad4 AMR exome AF: 0.000128

Gnomad4 ASJ exome AF: 0.00

Gnomad4 EAS exome AF: 0.00

Gnomad4 SAS exome AF: 0.00

Gnomad4 FIN exome AF: 0.00

Gnomad4 NFE exome AF: 0.00

Gnomad4 OTH exome AF: 0.00

GnomAD4 genome Cov.: 32

Bravo AF: 0.00000378

ExAC AF: 0.0000247 AC: 3

ClinVar

Significance: Conflicting classifications of pathogenicity

Submissions summary: Uncertain:7 Benign:2

Revision: criteria provided, conflicting classifications

Submissions by phenotype

Hereditary cancer-predisposing syndrome Uncertain:1 Benign:2

Likely benign, criteria provided, single submitter	clinical testing	Ambry Genetics	Jan 16, 2019	This alteration is classified as likely benign based on a combination of the following: seen in unaffected individuals, population frequency, intact protein function, lack of segregation with disease, co-occurrence, RNA analysis, in silico models, amino acid conservation, lack of disease association in case-control studies, and/or the mechanism of disease or impacted region is inconsistent with a known cause of pathogenicity. -
Likely benign, criteria provided, single submitter	curation	University of Washington Department of Laboratory Medicine, University of Washington	Mar 23, 2023	Missense variant in a coldspot region where missense variants are very unlikely to be pathogenic (PMID:31911673). -
Uncertain significance, criteria provided, single submitter	clinical testing	Color Diagnostics, LLC DBA Color Health	Mar 01, 2023	This missense variant replaces arginine with lysine at codon 324 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with breast cancer (PMID: 25186627). This variant has been identified in 4/232690 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -

Breast-ovarian cancer, familial, susceptibility to, 2 Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	All of Us Research Program, National Institutes of Health	Jun 08, 2023	This missense variant replaces arginine with lysine at codon 324 of the BRCA2 protein. Computational prediction suggests that this variant may not impact protein structure and function (internally defined REVEL score threshold <= 0.5, PMID: 27666373). To our knowledge, functional studies have not been reported for this variant. This variant has been reported in an individual affected with breast cancer (PMID: 25186627). This variant has been identified in 4/232690 chromosomes in the general population by the Genome Aggregation Database (gnomAD). The available evidence is insufficient to determine the role of this variant in disease conclusively. Therefore, this variant is classified as a Variant of Uncertain Significance. -
Uncertain significance, criteria provided, single submitter	clinical testing	Counsyl	Jul 12, 2016	- -

not provided Uncertain:2

Uncertain significance, criteria provided, single submitter	clinical testing	GeneDx	Aug 15, 2022	Not observed at significant frequency in large population cohorts (gnomAD); In silico analysis supports that this missense variant does not alter protein structure/function; Observed in an individual with breast cancer (Tung et al., 2015); Also known as 1199G>A; This variant is associated with the following publications: (PMID: 26343386, 29884841, 29618726, 28569743, 25186627, 32377563) -
Uncertain significance, criteria provided, single submitter	clinical testing	Quest Diagnostics Nichols Institute San Juan Capistrano	May 19, 2022	- -

not specified Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Women's Health and Genetics/Laboratory Corporation of America, LabCorp

Aug 09, 2023

Variant summary: BRCA2 c.971G>A (p.Arg324Lys) results in a conservative amino acid change in the encoded protein sequence. Five of five in-silico tools predict a benign effect of the variant on protein function. The variant allele was found at a frequency of 1.7e-05 in 232690 control chromosomes. The available data on variant occurrences in the general population are insufficient to allow any conclusion about variant significance. c.971G>A has been reported in the literature in at-least one individual affected with breast cancer (Tung_2015). This report does not provide unequivocal conclusions about association of the variant with Hereditary Breast And Ovarian Cancer Syndrome. To our knowledge, no experimental evidence demonstrating an impact on protein function has been reported. The following publication have been ascertained in the context of this evaluation (PMID: 25186627). Seven submitters have cited clinical-significance assessments for this variant to ClinVar after 2014 and classified as VUS (n=5) and likely benign (n=2). Based on the evidence outlined above, the variant was classified as uncertain significance. -

Hereditary breast ovarian cancer syndrome Uncertain:1

Uncertain significance, criteria provided, single submitter

clinical testing

Invitae

Jan 29, 2024

This sequence change replaces arginine, which is basic and polar, with lysine, which is basic and polar, at codon 324 of the BRCA2 protein (p.Arg324Lys). This variant is present in population databases (rs397507435, gnomAD 0.01%). This missense change has been observed in individual(s) with breast cancer (PMID: 25186627). ClinVar contains an entry for this variant (Variation ID: 141234). Advanced modeling of protein sequence and biophysical properties (such as structural, functional, and spatial information, amino acid conservation, physicochemical variation, residue mobility, and thermodynamic stability) performed at Invitae indicates that this missense variant is not expected to disrupt BRCA2 protein function with a negative predictive value of 95%. In summary, the available evidence is currently insufficient to determine the role of this variant in disease. Therefore, it has been classified as a Variant of Uncertain Significance. -

Computational scores

Source: dbNSFP v4.3

Name	Calibrated prediction	Score	Prediction
AlphaMissense	Benign	0.075
BayesDel_addAF	Benign	-0.33	T
BayesDel_noAF	Benign	-0.47
Cadd	Benign	3.0
Dann	Benign	0.25
Eigen	Benign	-0.93
Eigen_PC	Benign	-0.83
FATHMM_MKL	Benign	0.059	N
M_CAP	Benign	0.0082	T
MetaRNN	Benign	0.069	T;T
MetaSVM	Benign	-0.93	T
MutationTaster	Benign	1.0	N;N
PrimateAI	Benign	0.31	T
PROVEAN	Benign	-0.040	N;N
REVEL	Uncertain	0.35
Sift	Benign	1.0	T;T
Sift4G	Benign	1.0	T;T
Vest4		0.075
MutPred		0.14		Gain of methylation at R324 (P = 0.0311);Gain of methylation at R324 (P = 0.0311);
MVP		0.86
MPC		0.020
ClinPred		0.014	T
GERP RS		2.9
gMVP		0.14

Splicing

Name	Calibrated prediction	Score	Prediction
SpliceAI score (max)		0.0		Details are displayed if max score is > 0.2

Find out detailed SpliceAI scores and Pangolin per-transcript scores at spliceailookup.broadinstitute.org

Publications

LitVar

Other links and lift over

dbSNP: rs397507435; hg19: chr13-32906586; COSMIC: COSV66462906;